Electrical generation solar concentrators are subjected to high insolation, and at night or during obstruction of the sun by a cloud they become cooled. Liquid-cooled solar concentrator cells become cooled very rapidly during cloud obstruction during an otherwise clear summer day, and then re-heat very rapidly again when the concentrated solar radiation again impinges on the front face of the cell. Thus, the cell and its electrical contacts are subjected to thermal and mechanical stresses, which can lead to early failure during operation. Also, solar concentrators are often exposed to severe ambient weathering conditions in geographic regions of high insolation.